Pesto Portabella Cheesecake

1.5C. pesto
6 oz. Portabella (roughly 10 pieces of sliced portabella)
1/2 onion
1 TBS olive oil
2 block cream cheese softened
1 C. sour cream
3 large eggs
Tomato slices (about one tomato)
Parmesan

Line the bottom of a spring form with sliced tomatoes, and set aside. Sautee mushrooms and onions in olive oil. Combine cream cheese and sour cream and add onion and mushroom mixture, and pesto. Test seasoning. Add eggs. Pour over tomato slices in spring form and bake at 350 for 45-60 minutes. It is done when you stick a knife in and it comes out almost clean (not soupy). Let cool. Loosen sides of spring form and remove. Invert so that tomatoes slices are on top. Remove bottom of spring form and dust with Parmesan. This can be served warm or cold.

This is particularly good on bagels the next day! I have never tried sun-dried tomatoes but I think they would be great.